Spin-coating processes are commonly employed, for example, in the manufacture of semiconductor devices. A base plate or substrate, such as a silicon wafer is spun on a turntable or chuck. A coating liquid is deposited on the substrate and is spread over the entire surface of the substrate by the centrifugal force from the rotation of the substrate.
The rotatable chuck may be placed in a spin-coating chamber, and excess coating liquid may collect in the chamber when it exits the outer perimeter of the substrate. Some spin-coating chambers include a discharge drain for draining excess coating liquid. However, significant amounts of coating liquid may be lost in this configuration, which may increase the cost of production.